Quarter-wave Fresnel zone planar lens and antenna
نویسندگان
چکیده
منابع مشابه
Micro-patterned photo-aligned ferroelectric liquid crystal Fresnel zone lens.
In this Letter, we disclose a fast switchable Fresnel zone lens (FZL) by confining the ferroelectric liquid crystals (FLCs) in multiple microscopically defined photo-aligned alignment domains. The photo-alignment (PA) offers good control on the anchoring energy (W) by mean of irradiation doses (ID) and thus excellent alignment for FLCs. Two operational modes of the FLCFZL, i.e., FOCUS/OFF and F...
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Microstrip antennas are one of the most widely used types of antennas in the microwave frequency range, and they are often used in the millimeter-wave frequency range. Actually as the demand for high data rates grows and microwave frequency bands become congested, the millimeter-wave spectrum is becoming increasingly attractive for emerging wireless applications. The abundance of bandwidth and ...
متن کاملthe fresnel zone plate antenna as an electromagnetic field focusing element.
fresnel zone plate antenna (fzpa) was considered as a recieving antenna. an expression of electric field on axis of antenna produced by an incidente plane wave was found . the expression was used for calculation of gain, efficiency and optimum phase correcting function. several fzpa are fabricated and tested. experimental and theoretical results were compared and it was shown that there was a g...
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The use of dual polarization in meteorological radars offers significant advantages over single polarization. Recently a standard single-polarization C-band radar was upgraded to operate in dualpolarization mode. The antenna has a 4.2m diameter parabolic reflector with a prime-focus feed. A spherical Fresnel-zone holographic technique was used to obtain the radiation pattern for the upgraded an...
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ژورنال
عنوان ژورنال: IEEE Microwave and Guided Wave Letters
سال: 1995
ISSN: 1051-8207
DOI: 10.1109/75.401077